基于无人机多光谱遥感的夏玉米冠层叶绿素含量估计

为探讨利用无人机多光谱遥感影像监测夏玉米冠层叶绿素含量的可行性,基于2019年不同施氮水平下(0,105,210,315 kg·N/hm²)夏玉米多光谱遥感影像和田间实测冠层叶绿素含量数据,分析了不同施氮水平下夏玉米冠层叶绿素含量的变化规律,同时选取10种常用光谱植被指数与实测冠层叶绿素含量进行相关性分析,采用与实测叶绿素含量极显著相关的9种植被指数,构建了基于遥感光谱指数的夏玉米冠层叶绿素含量遥感监测模型,并通过精度检验确定最优估测模型.结果表明,施用氮肥能够提高夏玉米冠层叶绿素含量,过量氮肥不能持续提高叶绿素含量,同一施氮水平下不同追肥处理之间叶绿素含量没有明显差异.绿色归一化植被指数与叶绿素含量的相关性系数最高,达到了0.892.采用逐步回归分析方法建立的模型表现最优,决定系数为0.87,均方根误差及相对误差分别为0.15和2.68%.因此,无人机多光谱遥感结合逐步回归模型可以实现田间尺度的夏玉米冠层叶绿素含量的实时监测.     

海产食品中药理活性成分研究进展

对近几年来海洋水产食品中抗肿瘤、抗菌抗病毒、抗溃疡、抗心血管疾病等方面的活性物质的研究进行了综述，旨在为水产品的开发和综合利用提供帮助。     

黄海鳀鱼鱼体能值的季节变化

根据2002年6月～2003年9月黄海中南部水域鳀鱼的调查资料,分析了产卵、索饵和越冬期鱼体能值的季节变化以及精巢和卵巢能值的变化情况。产卵期(5～7月)、索饵期(8～10月)和越冬期(11～1月)鳀鱼能值的变动情况反应了性腺发育状况。卵巢能值和精巢能值的季节变化趋势相似。幼鱼和成年鳀鱼能值的季节变化趋势相似,但各个月份幼鱼能值均比成鱼低。鱼体能值从越冬期到产卵前期变化很大,达40％～50％,这主要由脂肪含量变化引起。湿重丰满度系数比干重丰满度系数估算鱼体能值准确度差。     

龙池鲫DNA含量、倍性分析及其形态学特征研究

以鸡(Gallus sp.)红细胞DNA含量(2.5 pg/N)为标准对照,利用流式细胞术测定了龙池鲫(Carassius auratus in Long Lake)的红细胞核DNA含量,采用T型标技术标记了2倍体与3倍体龙池鲫并研究了2倍体与3倍体龙池鲫的形态特征,为阐明龙池鲫的遗传背景及资源增殖保护提供科学依据。结果显示,实验检测的265尾龙池鲫中,42尾龙池鲫样品红细胞核的相对DNA含量接近76,占15.85%,223尾样品接近110,占群体数的84.15%;二倍体龙池鲫的DNA含量为3.83 pg/N,三倍体龙池鲫的DNA含量为5.38 pg/N。龙池鲫是由二倍体和三倍体两种类型的鱼组成的混合群体;侧线鳞数量可作为二倍体龙池鲫与三倍体龙池鲫的辨别参考指标。T型标暂养1周后龙池鲫的成活率达到100%,脱牌率为1.13%。     

Determination of primary structure of amberjack myosin heavy chain and its relationship with structural stability of various fish myosin rods

The structural stability of fish myosin depends upon species and temperatures of water in which fish live. Primary, secondary, and quaternary structures of myosin heavy chain (MyHC) from three species of fish living at different temperature ranges have been compared with those of rabbit MyHC in order to investigate the differences in stability. Primary structure of MyHC, although being accessible for warm-water and cold-water fish (carp and walleye pollack), was not available in previous for tropical-water fish literature; so in this study primary structure of MyHC of the tropical-water fish amberjack has been determined by cloning and sequencing its cDNA. The MyHC has 1938 amino acid residues (AA), which are almost as much as as those of carp and walleye pollack. The amberjack MyHC is 91–95% homologous with other fish and rabbit MyHCs. There is a discernible difference between animal species with stable myosin rod (amberjack, carp, and rabbit) and walleye pollack with unstable rod. Stable rod species have a high probability of forming coiled-coil around the COOH-terminal end of the rod, while the pollack has a low coiled-coil formation probability. In addition, the average scores of the coiled-coil for myosin rod were rabbit (1.738) > amberjack (1.691) > carp (1.680) > walleye pollack (1.674) which correlated exactly with the observed stability. The results suggest that coiled-coil forming ability, particularly around the COOH-terminal end, directs structural stability of fish myosin rod.     

Guanine-cytosine contents of the host and symbiont cDNA in a symbiotic coral

ABSTRACT:   Hermatypic (reef-building) corals harbor dinoflagellate endo-symbionts Symbiodinium spp. In studying gene expression in such symbiotic corals, problems arise regarding how to distinguish the coral and symbiont mRNA, and how to estimate their fractions in the mRNA population of the holobiont (symbiotic complex of the coral and Symbiodinium cells). In this study, these issues were addressed using juveniles of hermatypic coral Acropora tenuis in symbiosis with Symbiodinium cells of strain PL-TS-1. First, the guanine-cytosine (GC) contents were determined in expressed sequence tags (EST) from PL-TS-1 cells cultured in vitro and symbiont-free larvae of A. tenuis , and their average GC contents were found to be significantly different. The average GC content of the EST from the holobiont was much closer to that of A. tenuis larvae, suggesting that the majority (>90%) of mRNA isolated from the holobiont originated in the host. In protein-coding sequences, little overlap was observed between the GC-content distributions of PL-TS-1 cells and A. tenuis larvae. All of the coding sequences ( n  = 59) found in the A. tenuis EST had GC contents below 0.5, whereas the GC content exceeded 0.5 in the majority (43/44) of coding sequences from the nuclear genome of PL-TS-1 cells.     

锦鲤尾鳍细胞系(KF-H)的建立

本研究建立了锦鲤(Cyprinus carpio)尾鳍细胞系。染色体数目、核型及DNA含量等实验,发现锦鲤体细胞和锦鲤培养细胞无显著性差异,染色体数目和DNA含量符合比例关系,建立的锦鲤尾鳍细胞系已形成了稳定的遗传性状,命名为KF-H。     

成体瘤背石磺不同组织中的重金属含量及其评价

采用原子吸收法测定了瘤背石磺栖息地(崇明北支芦苇滩涂)的水质、土壤及成体瘤背石磺不同组织中的各项重金属含量,并与相应的国家标准进行了比较。结果表明:瘤背石磺栖息地的水质和土壤基本符合相应的国家标准,仅土壤中的Cu和Zn含量略超过国家标准《土壤环境质量标准》,污染指数分别为1.39和1.09。瘤背石磺肝胰腺中积累了较多的Cu、Zn和Fe,含量分别高达314.33、258.33和192.40μg/g组织湿重,两性腺中的Zn含量为309.33μg/g组织湿重,显著高于其它组织(P<0.05),肌肉和卵黄腺中的重金属含量均较低。除Cd含量外,瘤背石磺肌肉中的其它重金属含量均符合国家标准《农产品安全质量:无公害水产品安全要求》中的规定要求,但是肌肉中Cd含量远低于CAC标准(国际食品法典委员会标准)规定的2.0μg/g湿重。     

南极磷虾木瓜蛋白酶酶解产物的营养学评价

分析了经1.5%木瓜蛋白酶55℃酶解3 h后的南极磷虾(Euphausia superba)蛋白酶解产物(上清和沉淀)的营养组成。结果显示:南极磷虾水解度为44.24%;上清冻干物(FDS)中粗蛋白和总糖含量分别为67.13%和13.91%,其必需氨基酸总量(ΣEAA)、鲜味氨基酸总量(ΣDAA)、牛磺酸Tau含量及F值(支链氨基酸/芳香族氨基酸)较酶解前分别提高了8.96%、6.06%、39.10%和16.67%,表明其氨基酸营养价值较酶解前要高。沉淀冻干物(FDP)中粗蛋白和总糖含量分别为44.49%和10.40%,而粗脂肪含量高达33.28%。FDP中总氨基酸含量(ΣAA)、ΣEAA、ΣDAA、Tau含量及F值均下降,但其ΣEAA在ΣAA中的比例高于40%,且8种EAA含量评分均高于FAO/WHO评分模式要求。脂肪酸分析结果表明,FDP中含有饱和脂肪酸(SFA)8种(44.81%),单不饱和脂肪酸(MUFA)6种(27.55%),多不饱和脂肪酸(PUFA)7种(27.64%),二十碳五烯酸EPA和二十二碳六烯酸DHA含量较丰富。研究认为在本实验条件下通过木瓜蛋白酶酶解南极磷虾得到的FDS和FDP具有较高的利用价值,可开发为人类重要的蛋白来源。     

营养盐浓度对棕鞭藻叶绿素荧光参数、细胞密度和总脂含量的影响

利用生物化学方法和叶绿素荧光动力学分析技术,研究了棕鞭藻在一次性培养过程中,不同营养盐浓度(f/4、f/2、f、2f、4f)对其叶绿素荧光参数、叶绿素含量、细胞密度、单位体积干质量、总脂含量和总脂收获量的影响。试验结果表明,营养盐浓度为2f时,该藻的最终细胞密度、叶绿素含量、单位体积干质量、总脂含量和总脂收获量均显著高于其他各处理组,由此可以看出,在本试验条件下,最适合棕鞭藻生长和油脂积累的营养盐浓度是2f。不同营养盐浓度对棕鞭藻的叶绿素荧光参数有显著影响,培养6～10d,f/4处理组的叶绿素荧光参数(光系统Ⅱ的最大光能转换效率;光系统Ⅱ的潜在活性;光系统Ⅱ的实际光能转化效率;相对电子传递效率和光化学淬灭)最低,其次为f/2处理组(P0.05)。培养7～10d,2f处理组的光系统Ⅱ的实际光能转化效率、相对电子传递效率和光化学淬灭显著高于其他处理组(P0.05)。培养结束时(第10d),各处理组细胞密度和总脂含量依次为:2f4fff/2f/4。相关性分析结果表明,营养盐浓度为f/4～2f时,棕鞭藻的细胞密度、叶绿素含量、单位体积干质量和总脂含量与营养盐浓度均呈显著的正相关;营养盐浓度为2f～4f时,上述各值与营养盐浓度则均呈显著的负相关。